Set SCHEME to the bigloo interpreter.
Don't set *hygien?* and don't attempt to redefine load.

I believe these are simply no longer needed in recent versions of
bigloo, but I'm leaving them commented out with a TODO until I can
verify (the bigloo homepage is down for some reason and I can't get
to the docs...).
Fix chap1 test. Bigloo is apparently now case sensitive.
Add .gitignore
Don't attempt to redefine bigloo read-only builtins.

odd?, even?, and getprop and read-only in bigloo.
Explicit call to expand-syntax is no longer needed in bigloo.
Allow overriding of memq implementation used in vowel* procedures.

Bigloo doesn't allow direct redefinition of the read-only memq
builtin, so introduce a global var *memq* and override that in
the test file.
Refactor defines with a list in the call position to standard form.

From the book, p. 175:

  Here we've used the outmoded for define that allowed a first
  argument in the call position. The form (define (v . variables) pi*)
  is recursively equivalent to (define v (lambda variables pi*))
  where v can still be a form of calling.

Thank goodness for this note from the author! Being a scheme noob
I was not sure how to translate it and googling prooved fruitless.

Apparently, Bigloo no longer supports this obsolote form of define.
Fix inconsistent case: InValue -> inValue.

Bigloo is case-sensitive by default now.
Refactor obsolete define syntax for all ch 5 interpreters.
Don't redefine read-only builtins.
Fix case: test-Scheme6x -> test-scheme6x
Don't redefine read-only builtin.
Fix case: test-Scheme7x -> test-scheme7x
Don't redefine vector-copy!
Ignore tmp.si directory.
Ignore build and temp files in tmp.si directory.
Don't redefine vector-append!.

Also, change vector-copy! -> _vector-copy!.
Load the correct fib.so file.

The file si/fib.so is not the same as tmp.si/fib.so. For one, Bigloo is
now case-sensitive, so the file in tmp.si/ defines the global ``fib'',
whereas the file in si/ defines ``FIB''. More importantly, the file in
si/fib.so is missing a bytecode, SHALLOW-ARGUMENT-REF1 (bytecode 2),
which is the sith bytecode from the start (zero-indexed) in
tmp.si/fib.so.

Attempting to load si/fib.so in tmp.si/after.scm was resulting in a
runtime execption when attempting to call CALL2-= with a boolean #f in
the *arg1* parameter. The exception was causing test.chap7g to fail.
Delete .so files that should be generated by the build.